KR910005154B1 - Method for manufacturing multi hardness for amed articles - Google Patents

Abstract

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Description

Method for producing multilayer two-hard foam

1 to 5 relate to a first embodiment of the method of the present invention,

1 is a schematic cross-sectional view showing the step of injecting into the mold.

2 is a plan view of the mold for explaining the injection site and the direction of flow and diffusion.

3 is a cross-sectional view showing a step of foaming by closing the cover.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 2 in which the foam product produced by the method of the first embodiment is taken out of the mold and inverted.

5 is a cross-sectional view taken along line V-V of FIG.

6 to 9 relate to a second embodiment of the method of the present invention,

6 is a schematic cross-sectional view showing a step of injecting two layers into a mold for the first time.

7 is a plan view of a seat cushion product manufactured according to the second embodiment.

Fig. 7 is a cross sectional view taken along the lines VIII-VIII and IX-IX of Fig. 7 showing the three-layer structure according to the method of the second embodiment of Figs.

10 and 11 illustrate a conventional fourth method.

10 is a perspective view showing an initial injection.

FIG. 11 is a perspective view showing a cross section of a completed two-hard foam.

The present invention relates to a method for producing a multilayer two-dimensional foam.

For example, as a cushion pad material for a vehicle seat, what laminated | stacked two or more foams from which hardness differs conventionally is known.

One of the conventional manufacturing methods is to separately cut and paste the foamed two-hard foams into required shapes and dimensions, but this requires labor and time for each molding operation, and also requires time and effort for joining operations. There was a significant shortcoming that it was difficult to obtain high quality products.

The conventional second method is to first mold a foam of a certain hardness, and then to inject a second composition of a different hardness into the foam molding, and to integrate the two, but this method is also cumbersome in manufacturing process. The major drawback was that the boundary between layers could not be completed as intended.

As a third method, there is a method disclosed in U.S. Patent No. 3,257,149 (June 21, 1966), which is a method of installing a partition in a mold and foaming the two liquids so as not to mix with each other. It's a losing classic.

As the fourth most advanced method compared to these methods, there is a method described in JP-A No. 1980-96195 “Multilayer Non-foaming Product and Manufacturing Method Thereof”. The fourth method will be described briefly with reference to FIGS. 10 and 11, firstly, a first composition which becomes a rigid foam component in a molding die (a) having a lid (b) as shown in FIG. Partial injection of c) results in some foaming. Next, on the composition (c) which foamed to some extent, the 2nd composition (d) which becomes another hardness, ie, a flexible foam component, is inject | poured. Since the first composition (c) is relatively foamed, it is reduced in density, and the next composition (d) still sinks to the bottom of the mold past the first composition (c) because the specific gravity is still large in the liquid state. The composition (c) is suspended on the second composition (d). When the cover (b) is closed and both compositions (c) and (d) are expanded and cured, foams (C) (hard) and (D) (lead) having different hardness are integrated into a plurality of layers as shown in FIG. One foam product is obtained. When used as a cushion, it is reversed so that the upper surface of the U side and the lower side of the R side are used. Since this cushion is supported by the flexible foam D on the rigid foam C, a complex seating comfort and a support feeling are obtained. However, there are some problems with the product by this method.

1) The hard 1st composition (C) mostly floats on the soft 2nd composition (D) and proceeds to foaming, but the first composition attached to the bottom of the mold remains as it is without falling off the bottom surface, and thus the U surface of the product. To form a thin layer (C ') of rigid foam components. This thin layer (C ') is an unintended product, and it is a kind of obstacle that damages the comfort, support, adhesion, texture, etc. by the flexible layer on the surface. There is also a risk.

2) The R side on the back of the product is formed of the solid foam component (C) foamed by the first injected composition (c), but the traces of penetrating the second composition (d) injected later therefrom are marked with injection defects (D '). Appear together to damage the appearance of the product.

3) Similarly, at the time when the first composition (light) is relatively foamed, the second composition (flame) (d) is injected from above and passed in a liquid state, so that the cell in which the rigid foam (C) starts to harden is crushed to deteriorate the risk of deterioration. This is high and there is a risk of degrading the quality of the product, and because the difference in the injection time of the first and second compositions is too great, the adhesive strength between the two layers is low and the product is defective.

4) Injecting the second composition has to wait until the rigid foam component (C) foams considerably, with a loss time of up to 30 seconds or more, which impairs the efficiency of the overall process or length of the production line. There are many disadvantages such as the need for dialogue and the multiple installation of injection robots.

The present invention has been made to solve such problems as lack of comfort in the conventional multi-layered hard foam, product quality, appearance defects, length of manufacturing time, multiplexing of production equipment, and the like. Plural layers of two hardnesses are integrally bonded at regular boundaries without mixing with each other, and exhibit the intended comfort (support feeling, fit, texture), and the appearance and quality are excellent. The present invention also provides a method for producing a multilayer two-dimensional foamed foam which is short and has a simple production facility.

In order to achieve the above object, the present invention continuously and rapidly injects a plurality of liquid compositions, which are foams of different hardness, into the same point or approximately the same point on the bottom face of the forming mold inclined, and the preceding composition. On top of this layer of diffusion in the liquid state, the next liquid-state composition of another layer is diffused in the same orbit in the same direction as the preceding composition, so that the respective layers are not mixed with each other at the interface and are integrally It is made to foam by hardening in the joined state.

In the present invention, "continuously rapid" means that the next liquid composition is injected without giving time to substantially foam the first injected liquid composition, and the first injection and subsequent injection The time difference between the ones is from 0 seconds to about 7 seconds, so-called cream time.

Conventionally, it was common knowledge in the industry to think that two or more foamable compositions in a liquid state overlapped and mixed with each other without forming an interface. However, the inventors reversed this common sense, and the foamed composition first injected into a liquid state and Subsequent foaming compositions injected directly thereon in a liquid state are never mixed, find a clear and square interface, foam each, and integrate, thus completing the present invention.

According to the present invention, even when the inclination of the bottom of the frame is close to 0 °, it is recognized that the liquid composition flows and flows from the injection point to the surroundings. However, in this case, the diffusion method of each layer is often not uniform. , It is necessary to incline to the bottom of the frame to some extent, and it is preferable to incline more than about 4 °. On the other hand, the upper limit of the inclination is about 40 °, and the flow of the liquid composition is not very fast, and a multi-layered two-hard foam can be obtained. However, since a large amount of the liquid composition is easy to collect on the downstream side of the inclination, it is preferable. Slope up to 20 degrees is good. The most suitable range of inclination was recognized as 5-12 °.

Then, the liquid composition injected onto the inclined frame surface flows and expands so as to be gradually pushed upwards slightly from the injection point, and accordingly, in the present invention, the liquid composition can flow and spread with the attention of the injection point.

Next, the Example of this invention is described, referring drawings. 1 to 5 show a first embodiment of the method of the present invention and the product thereof, in which FIG. 1 is a schematic cutaway sectional view showing the step of injecting the mold, and FIG. 2 is a plan view of the mold, 3 4 is a cross-sectional view showing a step of closing and foaming the cover, FIG. 4 is a cross-sectional view corresponding to the IV-IV line 2 of the product according to the method of the first embodiment, and FIG. 5 is a cross-sectional view corresponding to the VV line of FIG. .

Example 1

The bottom face 2 of the aluminum frame 1 (FIG. 1) of 300 x 300 x 50 (mm) is kept at an inclination of an angle θ of 5 to 10 degrees with respect to the horizontal, and is about 55 deg. C with an electric heater in advance. After preheating, the first liquid composition A of the compounding formula (1) shown next to the point P of the center high side of the bottom face 2 as a low pressure foaming machine (Shin Admiral Co., Ltd. 600-2 type) 90 g was injected under conditions of a discharge rate of 13 kg / min, a liquid speed of 1.8 m / sec, a liquid temperature of 22 ° C., and a liquid viscosity of 500 cps. Subsequently, 180 g of the second liquid composition B of the following formulation (2) was immediately injected into the same P point with a low pressure foaming machine (MEG-MINI type manufactured by Maruka Kakoki Co., Ltd.). The injection conditions were 9 kg / min of discharge rate, 0.45 m / sec of liquid velocity, 25 ° C. of liquid temperature, and 800 cps of liquid viscosity.

(1) Acrylonitrile copolymerized polyether polyol (OH value 28) made by Asahi Glass Co., Ltd.

(2) Asahi Glass Co., Ltd. polyether polyol (OH value 33)

(3) Toyosu Oda triethylene diamine

(4) Nippon Yunika Silicone Foaming Agent

(5) Asahi Glass Co., Ltd. proorocarbon foaming agent

(6) MD Kasei Isocyanate

Representative Properties of Foam

Density 0.053g / cm ³

Indentation Load 16Kg / 314cm ²

Type F Lava Tester Surface Hardness 32。

Notes (1)-(4) are as above.

(7) Sumitomo Bayer Co., Ltd.

(8) Mitsui's Atsuga gaku triren isocyanate prepolymer (free isocyanate 29,6%)

Representative Properties of Foam

Density 0.067 g / cm ³

Indentation Load 46Kg / 314cm ²

Type F Lava Tester Surface Strength 80。

Referring to FIG. 1 and FIG. 2, since the first composition A injected first is in a liquid state, the first composition A is gradually pushed upwards somewhat on the bottom surface 2, but most of them diffuse in the horizontal direction (FIG. 2, X direction). It gradually flows to the lower side (second degree Y direction) of the bottom and spreads. The lower surface a of the first layer A that flows and diffuses partially adheres to the bottom surface 2. The second liquid composition B is injected onto the liquid first composition A by the injection hole 3 at the same point P as the first injection point. At this time, the second composition B has the same density as the first composition A. The second composition B diffuses in the form of a layer on the same trajectory as the first composition flows and diffuses on the layer of the first composition A sticking to the mold surface. In the meantime, the two layers (A) and (B) also start foaming little by little, but because the injection interval of the two compositions is short (0-3 seconds), the two layers do not mix with each other, forming a distinct interface. Flows along the same trajectory in the same direction.

Then, as shown in FIG. 3, the whistle 4 was closed, clamped (not shown), and foamed, expanded, and cured for about 5 minutes. At this time, the foam partitions and integrally joins the interface (f) in which the soft component (A) derived from the first composition and the hard component (B) derived from the second composition are clear. Since the first composition (A) becomes pale yellow, for example, the interface (f) can be visually confirmed after foaming by incorporating a blue colorant into the second composition (B).

This integrally bonded multi-layered two-hard foamed body was taken out of the mold 1, the independent bubbles were communicated by pulverization, and the curing was continued again.

The cross section of this foam is shown in FIG. 4 and FIG. 5 (the thing which took out of the frame and inverted). 4 is cut vertically (corresponding to the IV-IV line in FIG. 2), and the light foam component (A) and the rigid foam component (B) have a uniform thickness in the longitudinal direction. 5 is cut horizontally (corresponding to the V-V line in FIG. 2). The light foam component A injected first is thick at both edges and thin at the center. When the surface hardness was measured by the type F labater, it was 35 degrees on the surface (a) and 78 degrees on the back surface (b).

Further, in the same manner as in Example 1, the first liquid composition can be injected as a hard, and the second liquid composition as a soft, to obtain a multi-layered hard foam.

Example 2

First, the sole 11 as shown at the end face in FIG. 6 is adjusted to a mold temperature of 50-55 ° C. by a hot air circulation path, and the inclination angle θ with respect to the horizontal of the bottom 12 is 7-12 °. Maintained. A high-pressure foaming machine with a MEG-HK 650 type four-component MQ head made by Japan's Maruka Kakoki Co., Ltd. was used as the foaming machine, and the first liquid composition (lead) shown in the compounding (3) was then A side. In combination, the second liquid composition (light) shown in the formulation (4) can be continuously injected while switching to the undiluted stock solution in the same inlet 13 as the B-side combination.

Noted before (3).

(9) polyether polyol (OH value 33) made by Mitsui Atsuga Chemical Co., Ltd.

(10) Acrylonitrile copolymerized polyether polyol made by Mitsato Atsuga Chemical Co., Ltd. (OH value 28)

(11) UCC-Amine Catalyst

(12) Torre silicon silicone foam stabilizer

(13) Sumitomo Bayer urethane isocyanate

Representative Properties of Foam

Density 0.044 g / cm ³

Indentation Load 20Kg / 314cm ²

Type F Lava Tester Surface Hardness 48。

Note (3) (4) (9) (10) (11) (13) all before.

Representative Properties of Foam

Density 0.045 g / cm ³

Indentation Load 30Kg / 314cm ²

Type F Lava Tester Surface Hardness 75。

Referring to FIG. 6, the A side (first composition) of the high-pressure foaming machine is discharged 18 Kg / min, liquid velocity 1.1 m / sec, slightly below the rib 17 at the top of the bottom 12. A liquid temperature of 28 ° C. and a liquid viscosity of 280 g were injected at a condition of 500 cps. Immediately, 280 g of the B side (second composition) was injected under conditions of a discharge amount of 18 Kg / min, a liquid speed of 1.1 m / sec, a liquid temperature of 30 ° C., and a liquid viscosity of 800 cps. These first and second injection sites are circled with numbers 1 and 2 on the top view of the seat cushion of FIG. After about 3 seconds, the injection port 13 was moved to the upstream side of about 7 mm, and 120 g of the A side (the first composition) was injected again under the same conditions. This injection is indicated by 3 in FIG. Subsequently, 190 g and 220 g of B side (second composition) were injected into the left and right sides, respectively. This injection is indicated by ④ and ⑤ in FIG.

In the present invention, it is important to approach the injection time of the three-layer composition consisting of ABA 'of the central portion (the portion constituting the sheet portion 22 in FIG. 7), and the reaction rate, liquid properties and phase of each other can be adjusted. Similarly, since the injection site is intimately injected and continuously injected, the later injected liquid slides and spreads over the preceding liquid in the same trajectory as the flow of the first injected liquid.

When all the injections are finished, the whistle 14 is closed, clamped (not shown), foamed and cured. After 5 minutes, the whistle 14 is opened. The obtained foam is taken out of the mold 11 and crushed. Communication was made.

The top view of the product (seat cushion) thus obtained is shown in FIG. The center seat portion 22 is formed on the inclined bottom surface of the base 11, and the side portions 23 and 24 that rise from the left and right sides are recessed portions of the circumferential edge of the mold 11 (not shown, but the rear part). Is the same as the recess 18). The rear ridge 28 is formed in the recessed portion 18 of the mold, and the narrow slit 27 formed around the seat portion 22 is the rib 17 of the inclined peak of the mold 11 and the like. It is formed by ribs not shown.

8 and 9 are cross-sectional views cut along lines VIII-VIII and IX-IX of FIG. 7, respectively, in which the interface of the seat cushion 22, which is particularly central, is integrally bonded to the soft-hard-lead. It is recognized that it has a three-layer structure. In addition, since it is clear in FIG. 8, 9, the 1st composition (lead) injected into 3rd is made into A ', and is shown distinguishing from the 1st composition (A) injected first. Recesses 25 and 26 are formed on the lower surface of the seat cushion in correspondence with the protrusions 15 and 16 of the whistle 14.

Surface hardness measured by Type F lavatester was 48 ° at the surface of A, 49 ° at the back of the same location (lower surface of A '), and 68 ° at the top of B (blue) at 25mm from the surface of A. It was.

And the foam of B (light) A (lead) B (light) can also be obtained by the method similar to Example 2.

Example 3

As a compounding composition, the polyurethane foam stock solution system H 255 / H210 by Sumitomo Bayurethane Co., Ltd., Japan was used. This stock solution is commonly referred to as MDI cold-cured urethane foam stock solution, H 255 is a mixture of polyether polyol and catalyst foaming agent, H 210 is an isocyanate mainly composed of diphenylmethane diisocyanate, H 255 and H 210 The hardness of the foam can be arbitrarily changed by changing the mixing ratio of. Three representative examples of the mixing ratio and the hardness are shown in Table 1, but it is possible to change them substantially without steps.

Table 1

Using the same mold as in Example 2, the mold temperature was adjusted to 53-58 ° C., and the bottom was held at 5-12 ° relative to the horizontal plane. As a foaming machine, the thing with the MEG-HK430 type MQ head made from Japan Maruka Kakoki Co., Ltd. was used. This foaming machine is capable of arbitrarily changing the discharge amount of H 210 isocyanate while injecting liquid or waiting time between injecting and injecting, that is, continuously changing as mixing ratio 1 to mixing ratio 2 or mixing ratio 3 to mixing ratio 1. You can. Moreover, the liquid discharged from the injection port can be injected as a smooth flow without being scattered.

Injecting 180g / min of the discharge rate 180kg / min, the liquid speed 1.1m / sec, the liquid temperature of 28 degreeC, and the liquid viscosity 700cps to the point of the center high point of a bottom face, then changing to mixing ratio 2, without stopping liquid injection. 240g was injected, and it further changed to the mixing ratio 3, and injected 120g. Next, 160g and 240g were injected into the side at the mixing ratio 3, respectively.

In the case of foam hardening and pulverization as in Example 2, each layer could not be visually determined due to the same undiluted solution, but the hardness was measured by a type F lavatester surface hardness tester by cutting with a band saw about 20 mm from the surface and the surface. The surface was changed to 38 °, 55 ° and 70 ° in order, and the back side was 75 °.

And the method of Example 3 can also be implemented to inject in order of the mixing ratio 3, 2, 1, and other order.

In the method of the present invention, it is hard to cause a problem in the process due to the difference in foaming speed, curing rate, density, etc. of different foam components, and simultaneous injection of different foaming components of a selected type substantially without time difference. As a result, a high quality foam product can be obtained in which a desired square interface is combined.

In addition to being used as a cushion pad material for automobile seats, the multilayer two-dimensional foamed foam of the present invention can be widely used as bedding for furniture or office chairs, sofas, beds or mats by various combinations.

According to the present invention, in contrast to the conventional common sense, two, three or more kinds of hardness compositions are substantially co-injected in the liquid state, and thus, foam layers having different types of softening by organic reaction are commonly interfaced during the curing process. Since the multi-layered two-dimensional foamed foam which is integrally bonded in the fabric is obtained, the comfort, support feeling, fit or feel of the foam pad which does not cause any deterioration or defects such as injection defects in any of the foam components can be variously as intended. It can be variously realized, and a foam product of higher quality and higher performance can be obtained.

Since the method of the present invention substantially simultaneously injects different types of foamable compositions, it is possible to eliminate the loss time and to significantly shorten the working time as a whole to increase the efficiency and to shorten the production line. Substantially simultaneous injection of different compositions can achieve a wide range of effects, such as reducing the number of injection robots and simplifying production equipment.

Claims (14)

The bottom surface of the mold is kept inclined with respect to the horizontal, and the first liquid state composition, which is a rigid foam component constituting the surface side of the product, is injected into or near the apex of the slope on this bottom surface, thereby obtaining the composition. And a second liquid composition, which adheres to the bottom of the mold and flows from the injection site to the surroundings and diffuses, and is a foam component having different hardness, which constitutes another part of the product, which is rapidly obtained after the injection. Another layer that does not mix with each other on top of the first liquid-state composition layer which is injected or flowed in the same or near place, so that the second composition flows and the second layer flows after the second layer These two layers are each foam cured in a non-mixing state with each other at regular common interfaces and elsewhere. Not the sum A method for manufacturing a multi-layer foam reducers also made to obtain a multi-layer foam reducers also bonded integrally at the common boundary surface. The method of claim 1, wherein the first liquid composition has a composition that forms a flexible foam component, and the second liquid composition has a composition that forms a rigid foam component. The method of claim 1, wherein the first liquid-state composition has a composition that becomes a rigid foam component, and the second liquid-state composition has a composition that becomes a flexible foam component. The method according to claim 1, wherein the bottom surface of the molding die has an inclination of 0.1-40 degrees with respect to the horizontal. The method for producing a multilayer two-dimensional foamed article according to claim 1, wherein the bottom surface of the molding die has an inclination of 4-20 degrees with respect to the horizontal. The method for producing a multilayer two-dimensional foam member according to claim 1, wherein the bottom surface of the molding die has an inclination of 5-12 degrees with respect to the horizontal. The bottom of the mold is kept inclined with respect to the horizontal, and the first liquid state composition, which is a rigid foam component constituting the surface side of the product, is injected into or near the apex of the slope on the bottom, and Injecting a second liquid composition, which forms a foam component of different strength, constituting different parts of the product quickly and rapidly after the injection, while the composition adheres to the bottom of the mold and flows carefully from the injection site. The second liquid composition spreads and the flow of the first layer is followed by a second layer with another layer that does not mix with each other on the layer of the first liquid composition that flows and diffuses at the same or near location. At least with the second composition, which makes it flow and diffuses, and then again quickly and makes up another part of the product to be obtained. The third liquid composition, which is another foam component, is injected onto the second liquid composition at or near the injection site, and as a separate layer, which is not mixed with each other on the second composition layer which flows and diffuses. The layers of the liquid composition of the pore are foamed and the flow of the second layer is followed by diffusion by the third layer and each of these three layers is foamed and cured without mixing with each other, at an orderly common interface and elsewhere. A method for producing a multilayer bimodal foam, which is obtained by obtaining a multilayer bimodal foam which is not mixed with each other and is integrally bonded at this common interface. 8. The method of claim 7, wherein the first and third liquid-state compositions have a composition that is more flexible than the second liquid-state composition. 8. The method of claim 7, wherein the first and third liquid-state compositions have a composition that is a harder foam component than the second liquid-state composition. 10. The multi-layered diaphragm having a composition according to claim 7, wherein the first liquid composition is more than the second liquid composition and the second liquid composition is more flexible than the third liquid composition. Method for producing a provocative foam. 8. The multilayer of claim 7, wherein the first liquid composition is higher than the second liquid composition and the second liquid composition is higher than the third liquid composition, each having a composition that in turn becomes a rigid foam component. Method for producing a two-hard foam. 8. The method according to claim 7, wherein the bottom surface of the molding die has an inclination of 0.1-40 degrees with respect to the horizontal. 8. The method according to claim 7, wherein the bottom surface of the molding die has an inclination of 4-20 degrees with respect to the horizontal. 8. The method according to claim 7, wherein the bottom surface of the molding die has an inclination of 5-12 degrees with respect to the horizontal.

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